1. Field of the Invention
The present invention relates to a microscope optical system, and more particularly to a microscope optical system having a sensor for acquiring a digital microscope image that need not be observed through an ocular lens. The present invention is also related to a digital microscope having the microscope optical system.
2. Description of the Prior Art
The most widely used microscope is a compound microscope having at least two lenses, an objective lens and an ocular lens, respectively mounted at two opposite ends of a closed tube to provide a greater magnification. The observer observing through the ocular lens sees an enlarged virtual image of the real image. The virtual image display method for projecting the virtual image through the ocular lens directly onto the retina of the observer's eyes generally makes the observer feel tired (namely, visual fatigue) because the exit pupil diameter of the ocular lens is very small and the movement sideways of the body of observer probably causes a little endless movements of the observer's eyes.
Recently, one conventional microscope employs a special connection device for coupling the microscope with a digital camera. Though the observer does not need to directly observe through the ocular lens of the microscope coupled with a digital camera, it is very inconvenient to carry the microscope loaded with the digital camera and the special connection device and to view the small display of the digital camera.
On the other hand, the conventional microscope has a fixed focal length and multiple objective lenses. When the observer wants to see the virtual images having different magnifications, the objective lens must be changed. For example, the observer must try to change the objective lens one by one from all the objective lenses when observing a different object.
Hence, it is needed to provide a digital microscope and a microscope optical system for resolving the shortcomings of conventional designs and devices.